SSRI and Autism: The Link May Not Be Clear

Ann Arbor, MIWhen it comes to finding a link between drugs and birth defects, such as the link between SSRIs and autism, the situation may be more complicated than thought. Although some studies suggest a link between the use of an SSRI and autism, some SSRI medications are used as autism drugs, to treat the side effects associated with autism. In other words, the same drugs that some studies suggest cause autism when used during pregnancy are also used to treat that autism.

Now, however, a study suggests that SSRI (selective serotonin reuptake inhibitor) medications are not as effective at treating autism as previously thought. Some SSRIs are used to treat the repetitive behavior in children with OCD or autism. But a recent analysis of 15 SSRI autism trials found that SSRIs are not effective at treating repetitive behavior.

According to Reuters (4/23/12), researchers uncovered 15 trials that supported the use of SSRIs in children with autism. Overall, only six of the 15 trials were included in the final study because the other trials either did not meet criteria for inclusion or because the studies were never published. Of the six studies, only three showed a benefit from SSRIs, while the other three showed either some or no benefit.

Furthermore, the benefits associated with the SSRIs decreased even further when researchers included data for the studies that were completed but not published. That led researchers to conclude that publication bias—when positive findings are published but negative ones are not—was responsible for the belief that SSRI medications are effective at treating autism.

The study, published in the journal Pediatrics, showed that while five studies found benefits for using SSRIs to treat behaviors associated with autism, another five studies were not published, even though they were completed. According to WebMD (4/23/12), publications are often reluctant to publish studies if the results of the study show that a medication or treatment does not work. But when researchers accounted for the five unpublished studies, they found that the actual effectiveness of SSRIs in autistic behaviors dropped to 12 percent, a benefit that could be caused simply by chance.

Add that to research indicating that use of SSRI medications while pregnant could increase the risk of having a child with autism, and the relationship between autism and SSRI medications becomes even more complex. According to a study published in the Archives of General Psychiatry (7/11), use of an SSRI was modestly associated with an increased risk of autism spectrum disorder, especially when the SSRI was taken during the first trimester.